Activity #7: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science
Activity #7: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science
Activity #7: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science
Section/Group:
Subject: ANALYTICAL CHEMISTRY LAB
BACHELOR IN MEDICAL LABORATORY SCIENCE
ACTIVITY #7
INTRODUCTION
The current model of an atom includes a nucleus, consisting of protons, neutrons and electrons. Based on experiments on atomic
absorption and emission spectra, the energy of electrons is quantized. This means that each electron in an atom has a definite energy.
The energy of emitted or absorbed light is equal to the energy difference between the two energy states, and is inversely proportional
to its wavelength. When light is emitted by a large collection of atoms, a variety of energies and wavelengths are released as the electrons
return to their lowest energy states. When this light passes through a prism, a line spectrum is produced. Each line corresponds to a particular
energy and wavelength.
Each element exhibits its own characteristic line spectrum because the spacing of electronic energy states in atoms of various elements
is different. Thus, an example of this is the sodium atom which produces a yellow color while barium atom produces a green color.
OBJECTIVES
MATERIALS/CHEMICALS NEEDED
PROCEDURE
1. Do the cleaning procedure for nichrome wire by dipping the end of the wire into concentrated HCl and heating it in flame’s
hottest region until there is no visible color.
2. Repeat the cleaning procedure before dipping the nichrome wire into the different salt solutions.
3. Dissolve a pinch of CaCl2 crystals in 3-4 drops of distilled water contained in a watch glass.
4. Dip the pre-cleaned nichrome wire into the dissolved salt solution and heat it in the flame’s hottest region. Observe the flame
color produced.
5. Repeat the same procedure for the salt solutions.
6. Calculate the v (Hz), λ (nm), and E (J)
1. How is the flame test helpful in scientist/students who are conducting it during experiments?
Equation 1: E = hc/λ
Equation 2: E = hv
Where (E) is the energy of light
(c) is the speed of light (3.00 x108 m/s)
(h) is Planck’s constant (6.63 x 10-34 J)
(v) is the frequency of light
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430-490 blue
490-560 green
560-580 yellow
580-520 orange
620-800 red
4. Arrange the observed different flame colors accordingly to increasing energy and identify the salt
solution that emitted the largest amount of energy. Also, identify the salt solution that emitted the
smallest energy.
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